/Engine/Source/Runtime/Core/Public/Serialization/Archive.h
Sets mapping from offsets/ sizes that are going to be used for seeking and serialization to what is actually stored on disk. If the archive supports dealing with compression in this way it is going to return true.
true if archive supports translating offsets & uncompressing on read, false otherwise
virtual bool SetCompressionMap ( [TArray](API\Runtime\Core\Containers\TArray)< struct [FCompressedChunk](API\Runtime\CoreUObject\UObject\FCompressedChunk) > * CompressedChunks, ECompressionFlags CompressionFlags )